Substrate Bonding Apparatus Reducing Edge Exclusion
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Solution Overview
Problem
Conventional substrate bonding techniques result in large non-bonded edge regions, which reduce the usable area and weaken the substrate structure, and are often associated with complex and costly processes.
Innovation Solution
A method and apparatus that determine a characteristic length for each substrate by profiling its top surface from the interior to the edge, selecting substrates with a shorter characteristic length for bonding, and using a support system to expand the contact region radially from the center to the edges, minimizing the non-bonded edge exclusion region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional substrate bonding techniques are used, then substrates can be bonded together, but large non-bonded edge regions are formed reducing usable area and weakening structure
Solution Approach 1:
The substrate edges are pre-treated by rounding or removing sharp edges before bonding. This preliminary action eliminates the root cause of large non-bonded regions by modifying the edge geometry to enable better contact and bonding propagation from the center to the periphery
Solution Approach 2:
The bonding process parameters are optimized including applying controlled pressure and temperature conditions that promote bonding propagation from the substrate center toward the edges. The pressure is applied gradually to allow bonding to extend to the periphery rather than leaving large non-bonded regions
2Manufacturing precision
If conventional bonding processes are used, then substrates are bonded, but the process becomes complex and expensive when attempting to reduce edge exclusion
Solution Approach 1:
Instead of using complex bonding processes, the invention applies a simple preliminary edge treatment (rounding or removal of sharp edges) that enables conventional bonding processes to achieve excellent edge exclusion reduction. This avoids the need for complicated equipment or multi-step processes
Solution Approach 2:
The invention extracts and addresses the root cause of poor edge bonding (sharp edges) by removing or rounding them separately. This simple extraction of the problem element allows the rest of the bonding process to remain simple and conventional while achieving superior results
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively reduces the non-bonded edge exclusion region to as little as 1 mm, improving substrate quality while maintaining a simple and cost-effective manufacturing process, and is compatible with conventional technology.
Implementation Method 1
wafers 101 and 102 are bonded together by physical or chemical bonding forces
Implementation Method 2
wafers 101 and 102 are bonded together by physical or chemical bonding forces
Implementation Method 3
A heat treatment can be used to increase the bonding strength
Data Source
AI summary
An apparatus for bonding substrates includes a base member having a top surface and a recessed region which is configured for receiving at least a first substrate. The apparatus also has a plurality of support members disposed over the top surface for supporting a second substrate peripherally over the first substrate. Each support member is configured to vary a separation between the first substrate and the second substrate. Moreover, a pressure bar is configured to cause a center portion of the second substrate to contact the first substrate while the support members maintain peripheral separation between the first substrate and the second substrate. In operation, a bonded region between the first and the second substrates is expanded radially from the center portion when the support members are positioned to reduce the separation between the first and the second substrates.